1.1. Patient population. More than 500 coronary artery bypass surgeries (CABG) are performed annually at Jackson Memorial Hospital (JMH), the main teaching hospital of the U of M School of Medicine. The study coordinator works in close collaboration with Dr. Ricci, Co-Investigator. Dr. Ricci, working with other cardiac surgeons in his division, will screen all patients scheduled for CABG, and those who satisfy the eligibility criteria listed below will be invited to participate. Over a period of 37 months (between study months 4 and 41) 500 patients will be recruited and initially randomized to 2 groups: one (n=250) to receive conventional PRBC (unwashed PRBC) and the other (n=250) PRBC depleted of MP (washed PRBC). Approximately 50% of CABG will require PRBC transfusion during surgery and approximately 25% after surgery.